Tube plugging tool

ABSTRACT

A lance for positioning a plug comprised of a deformable sleeve disposed around a tapered cone at the remote end of a small diameter tube of a heat exchanger or the like is disclosed. A hydraulic actuator forces the sleeve around the tapered member to expand the sleeve into sealing engagement with the tube. In one general embodiment, a small hydraulic actuator is located at the end of the lance adjacent the plug and hydraulic fluid is supplied through the lance. In another general embodiment, the hydraulic actuator is disposed outside the tube, and the sleeve is forced around the tapered member by a tubular sleeve disposed around the lance. In each embodiment, the lance is disconnectable from the plug after the plug has been set. Several specific embodiments are also disclosed.

United States Patent Ice, Jr. et al.

[ TUBE PLUGGING TOOL [72] Inventors: Charles 0. Ice, Jr., Long Beach, Calif.; Lanny G. Ice; Walter S.

[21] Appl. No.: 22,613

[52] US. Cl. ..29/252, 138/89, 165/71,

165/76 [51] Int. Cl. ..B23p 19/02 [58] Field of Search ..29/252, 253, 202, 157.4;

[56] References Cited [15] 3,691,609 1451 Sept. 19, 1972 1,335,117 3/1920 Kofoedetal. ..138/91 Primary Examiner-Gil Weidenfeld Attorney-Richards, Harris & Hubbard [5 7} ABSTRACT A lance for positioning a plug comprised of a deformable sleeve disposed around a tapered cone at the remote end of a small diameter tube of a heat exchanger or the like is disclosed. A hydraulic actuator forces the sleeve around the tapered member to expand the sleeve into sealing engagement with the tube. In one general embodiment, a small hydraulic actuator is located at the end of the lance adjacent the plug and hydraulic fluid is supplied through the lance. In another general embodiment. the hydraulic actuator is disposed outside the tube, and the sleeve is forced around the tapered member by a tubular sleeve disposed around the lance. In each embodiment, the UNITED STATES PATENTS lance is disconnectable from the plug after the plug h b t. l 'f' b d 1 3,507,028 4/1970 Stellatella ..29/252x 1, 22; 85 Save Spec em "Hams are 2,950,525 8/1960 Duncan et al. ..29/252 3,457,987 7/1969 Lampe 165/76 14 Claims, 9 Drawing Figures 24 4 N l 7V 1 Ifi v 3e K36 4e PATENTED P 3.691.609

sum 1 [1F 3 FIG. 3

INVENTORS: WALTER S. FRAZER CHARLES 0. ICE, JR.

LANNY 6. ICE

ATTORNEYS FIG-i4 .VN/ENTGRS: WALTER S. FRAZER CHARLES 0. ICE, JR. LANNY 6. ICE

79W, Q4; WM

ATTORNEYS PATENTEDsEP 19 m2 3 591 509 sum 3 or 3 INVENTORS: WALTER S. FRAZER CHARLES 0. ICE, JR.

LANNY 6. ICE

ATTORNEYS TUBE PLUGGING TOOL This invention relates generally to a methodand apparatus for repairing heat exchangers, and more particularly relates to a tool for plugging the remote end of a tube of a heat exchanger tube bundle without removing the rear access plate of the exchanger shell.

Heat exchangers are widely used throughoutindustry to .transfertheat from .one fluid to another. One type of .heat exchanger comprises ,a cylindrical shell closed at each end by an access plate. A tube bundle is disposed within the cylindrical shell and is comprised of a very large number of small diameter, thin-walled tubes which extend between tube plates located at the ends of the tubes. The tube plates partition the center portion of theshell in which the tubes are located from the ends of the shell. One fluid is passed from one end of the shell through the tubes in parallel to the other ends of the shell. The second fluid is passed throughthe cen- .tral section of the shell around the tubes to achieve heat transfer between the fluids.

It is usually very important to keep the fluids separated. Since the fluids are often highly corrosive, the tubes are prone to develop leaks which results in the commingling of the two fluids. When this occurs it is usually economically desirable to plug the two ends of the leaking tube and continue operation of the heat exchange unit, rather than to replace the tube. At least one end plate of the shell must be removed togain access to the tube. Many tools have been usedtojsuccessfully plug the end of the tube adjacent the open end of the shell. However, at the present time, it is necessary to also remove the access plate from the rear end of the cylindrical shell. This is usually even more difficult than removing the front access plate and always requires a substantial period of down time of the unit. In addition, removal of the second plate often results in the loss of the product that is in the exchanger. A number of devices have been proposed for plugging the remote end of the tube without removing the second access plate, but none have achieved commercial success so far as is known. This task is made very difficult because of the very small diameter of the tube, typically threefourths inch, as compared to tile length, which may be as much as 40 feet.

This invention is primarily concerned with a tool for setting a plug at the remote end of a small diameter tube of a heat exchanger tube bundle, although the invention may also be advantageously used be set a plug at the near end of the tube. The invention comprises a hydraulically actuated too] for setting a plug having a sleeve member and a tapered member which may be forced into the sleeve member to expand the sleeve member into sealing engagement with the interior surface of the tube.

In a preferred form of the invention, the plug and a hydraulic linear actuator are both located 'on the end of a lance and passed through the tube to the position where the plug is to be set. Hydraulic fluid is then supplied to the hydraulic linear actuator through the lance to set the tool. The lance, and preferably also the linear actuator, are then disconnected from the plug and removed from the tube.

In another embodiment of the invention, the hydraulic linear actuator is not introduced to the tube, but the force produced by the hydraulic actuator is transmitted to the plug by way of a tubular sleeve disposed around the lance. The lance is again disconnected from the plug after it has been set. i

The novel features believed characteristic of this invention are set forth in the appended claims. The invention itself, however, as well as other objects and advantages thereof, may best beunderstood by reference to thefollowing detailed description of illustrative embodiments, when read in conjunction with the accompanying drawings wherein:

FIG. .1 is a somewhat schematic side view, partially in section, of a tOol in accordance with the present invention;

FIG. 2 is an enlarged sectional view of the hydraulic actuator of the tool illustrated in FIG. 1 and the plug set by the tool;

FIG. 3 is an enlarged sectional view similar to FIG. 2

illustrating the operation of the tool of FIG. 1;

FIG. 4 is a somewhat schematic side view, partially in section, of another tool in accordance with the present invention;

FIG. 5 is a sectional view of the: plug shown with the tool of FIG. 4;

FIG. 6 is a simplified longitudinal sectional view of the linear actuator of the tool of FIG. 4;

FIG. 7 is a simplified longitudinal sectional view of an alternative linear actuator for the tool of FIG. 4;

FIG. 8 is a longitudinal sectional view of yet another tool in accordance with the present invention; and,

FIG..9 is a longitudinal sectional view of still another tool in accordance with the present invention.

Referring now to the drawings, and in particular to FIG. 1, a tool in accordance with the present invention is indicated generally by the reference numeral 10. The tool 10 is shown in position within one of the tubes 12 of a tube bundle extending between tube sheets 14 and 16. The tube sheet 14 is disposed adjacent the front ac cess plate of a cylindrical shell (not illustrated) of a conventional heat exchange unit while tube sheet 16 is disposed adjacent the rear access plate. The present invention is particularly adapted to plug the end of the tube 12 atthe rear tube sheet 16 without removing the rear access plate that is disposed adjacent the tube sheet 16.

A suitable hydraulic pump 18 which may be a grease gun or any other conventional pump capable of generating substantial pressures, for example, on the order of 20,000 pounds, is connected by a flexible hose 20 and a coupling 21 to a tubular lance 22. The lance 22 may comprise a plurality of relatively short sections interconnected by suitable threaded couplings. A hydraulic linear actuator 24 is connected to the end of the lance 22, and a plug 26 is connected to the actuator. The actuator 24 and plug 26' are shown in greater detail in FIG. 2.

The hydraulic linear actuator 24 is comprised of a cylinder member 27 which is threadedly connected to the end of the lance 22. An axially disposed stem 28 is coupled by cylinder member 27 to the lance 22 and thus forms an extension of the lance. An annular piston 30 is slidably disposed around the stem 28 within the cylinder member 27. The piston 30 has interior and exterior O-rings 32 and 34 which provide sliding fluid seals between the piston 30 and the stem 28 and cylinder wall 27, respectively. The stem 28 has an annular shoulder 36 which engages an annular shoulder 38 on the piston 30 when the piston is fully extended to prevent the piston 30 from leaving the annular cylinder cavity as the lance is withdrawn from the tube as will presently be described. The stem 28 may be connected to the cylinder body 27 by a threaded coupling 40 to facilitate fabrication. A fluid port 42 provides fluid communication between the interior of the tubular lance 22 and the interior of the cylinder 27 behind the piston 30.

The plug 26 is comprised of a tapered member 44 which is connected to the stem 28, and thus to the lance 22, by a threaded coupling 46. The member 44 is fabricated from a relatively hard material such as steel. The threaded coupling 46 has threads opposite to those of all other threaded couplings in the lance 22 and linear actuator 24 so that the plug 26 can be separated from the linear actuator 24 and lance 22 after the plug has been set, as will be hereafter described in greater detail. For example, coupling 46 may have left-hand threads and all other couplings right-hand threads. An expandable sleeve 47 is disposed around the tapered member 44 and abuts the outer end of the piston 30. The sleeve 47 is formed of a malleable material, such as lead, and has an interior taper slightly less than the taper of the member 44. The outside diameter of the sleeve 47 is only slightly less than the diameter of the tube 12 which is to be sealed. However, it is preferred that the diameter of the extreme end of the tapered member 44 be slightly greater than the diameter of the sleeve 47 so that the member 44 will act as a scrapper and a gauge to insure that the plug can be passed into the tube.

To set a plug using the tool 10, the plug 26 is connected to the linear actuator 24 by threaded coupling 46. The linear actuator 24 is then connected to the lance 22, which may then be conveniently assembled as the lance is fed into the tube 12 which is to be plugged. Finally, the pump 18 is connected to the lance 22 by coupling 21. After the plug 26 has been positioned at the proper location within the tube 12, preferably within the tube sheet 16 as illustrated in FIG. 2, high pressure hydraulic fluid from pump 18 is introduced to the cylinder behind the piston 30 by way of the tubular lance 22 and port 42. The hydraulic pressure acting on piston 30 forces the sleeve 47 over the tapered member 44, thus expanding and wedging the sleeve 47 tightly between the member 44 and the interior surface of the tube 12, substantially as illustrated in FIG. 2. The hydraulic pressure is then released and the lance 22 rotated in a direction to disconnect coupling 46. It will be recalled that all other couplings in the lance 22 and the linear actuator 24 have oppositely pitched threads so that disconnection at coupling 46 is assured. The entire lance 22 and linear actuator 24 can then be withdrawn from tube 12.

Another embodiment of the invention is indicated generally by the reference numeral 50 in FIG. 4. The tool 50 is also illustrated in connection with a heat exchange tube 12 which is disposed in tube sheets 14 and 16 of a heat exchanger unit as heretofore described. The tool 12 is used to set a plug 52 (see FIG. 7) which is comprised of a deformable sleeve 54 and a tapered member 56. The tapered member 56 is coupled to a lance 58 by a coupling 60 having left-handed threads. The other end of the lance 58 is connected to the cylinder 61 of a linear actuator, indicated generally by the reference numeral 62 (See FIG. 7) having an annular piston 64 disposed within the annular cylinder cavity formed by the lance 58 and the cylinder 61. The piston 64 engages a tubular mandrel 66 which is disposed around the lance 58, and which engages the end of the deformable sleeve 54 of the plug 52. Both the lance 58 and mandrel 66 may be formed in sections interconnected by couplings having threads with righthanded pitch. High pressure hydraulic fluid is introduced through fitting 68 and port 70 to the cylinder of the actuator 62.

Operation of the tool 50 is substantially identical to the operation of the tool 10, except that the force from the hydraulic fluid introduced to the actuator 62 is transmitted from the piston 64 through the tubular mandrel 66 to drive the expandable sleeve 54 over the tapered member 56 and set the plug 52 in the desired position within the tube 12. After the plug 52 has been set in the tube 12, the cylinder 61 may be rotated in a direction to disconnect the left-hand threaded coupling 60. The lance 58 and mandrel 66 may then be withdrawn from the tube.

An alternative linear actuator for use in connection with the tool 50 is indicated generally by the reference numeral 71 in FIG. 7. The actuator 71 has a piston 72 disposed within a cylinder 74. The piston 72 is connected to the lance 58, and the end of the cylinder 74 engages the end of the mandrel 66. Hydraulic fluid is introduced through fitting 76 to the rod end of the cylinder so as to draw the lance 58 from the tube 12, and thus pull the tapered member 56 into the sleeve 54, to set the plug. In this arrangement, the sleeve 54 tends to remain stationary as it is expanded into contact with the interior of tube 12.

Another tool in accordance with the present invention is indicated generally by the reference numeral 80 in FIG. 8. The tool 80 is used in connection with a tubular lance and hydraulic pump such as indicated by the reference numerals 22 and 18, respectively, in FIG. 1. The tool 80 has a linear actuator indicated generally by the reference numeral 82 which is comprised of a cylinder member 84 and a piston member 86. The cylinder member 84 is connected to the lance by threaded coupling 88. The piston 86 has a first rod portion 89 which extends into a bore 90 where O-rings 92 provide a sliding annular seal. A second rod portion 94 extends from piston 86 through a bushing 96 which is connected to the cylinder 84 by a coupling 98 having left-hand threads. O-rings 100 provide an annular sliding fluid seal between bushing 96 and rod portion 94. High pressure hydraulic fluid is introduced from the tubular lance connected to coupling 88 to the interior of the cylinder adjacent the bushing 96 by way of bore 90 and port 102, which is shown in dotted outline. Port 103 vents the other end of the cylinder to atmosphere. The rod 94 extends through an expandable sleeve 104 of a plug, indicated generally by the reference numeral 106, and a tapered nut 108 is connected to the end of the rod 94.

In operation, the device 80 is connected to the end of the lance and positioned at the proper place within the tube 12, as heretofore described in connection with tool 10. Hydraulic fluid is then introduced under pressure through the lance, bore 90 and port 102 to the inwithdrawn from the tube, leaving the piston 86 includ- 0 ing rod portion 94, bushing 96, sleeve 104 and nut 108 within the tube. If desired, threaded coupling 88, rather than threaded coupling 98, can have a left-hand pitch so as to also leave cylinder 84 in the tube after the plug has been set. i

Another embodiment of the present invention is indicated generally by the reference numeral 110 in FIG. 9. The tool 110 is very similar to the tool 80 and has a hydraulic actuator indicated generally by the reference numeral 111. The actuator 111 is comprised of a cylinder 112 in which a piston 114 is reciprocably disposed. A rod 116 extends from the piston 114 into a bore 118 on the cylinder 112. Another rod 120 extends from piston 114 through a bushing 122 which is connected to the cylinder 112 by threaded coupling 124. O-rings 126, 128 and 130 provide the necessary annular fluid seals. The cylinder 112 is connected to a tubular lance, such as lance 22 of FIG. 1, by coupling 131. A fluid port 132 (shown in dotted outline) provides fluid communication between the bore 118 and the in terior of the cylinder 112 between the piston 114 and the bushing 122. A port 134 vents the interior of the cylinder on the other side of the piston 114 to atmosphere. A pin 136 is threaded into the bushing 122 and extends into a bore 138 which extends only partially through the piston 114 and prevents rotation of the piston 114 for decoupling purposes which will presently be described. The rod 120 is coupled to the tapered member 140 of a plug, indicated generally by the reference numeral 142 by a left-hand threaded coupling 144. An expandable sleeve 146 is disposed around tapered member 140 and abuts bushing 122.

The operation of the tool 110 is similar to that of the tool 10. After the plug 142 has been positioned at the appropriate place within the tube 12 by the tubular lance, hydraulic fluid is introduced under pressure to the interior of the lance and passes through bore 118 and port 132 to the interior of the cylinder 112 between the piston 114 and the bushing 122. ,T his pulls the tapered member 140 into the sleeve 146 which is held in place by bushing 122, thus expanding the sleeve 146 into engagement with the interior surface of the tube. After the plug 142 has thus been set, the lance is pulled back to move piston 114 against bushing 122 and then rotated in a direction to disconnect left-hand threaded coupling 144. The pin 136 transmits torque to the piston 114 and rod 120 as the lance is turned. The lance and the entire actuator 111 can then be withdrawn from the tool, leaving only sleeve 146 and tapered member 140 in place.

Although several preferred embodiments of the invention have been described in detail, it is to be understood that various combinations of the features illustrated in the several embodiments can be combined in a single tool, and that other changes, substitutions, and alterations can be made in the various parts without departing from the spirit and scope of the invention as defined by the appended claims.

What is claimed is:

1. A tool for plugging a heat exchanger tube which comprises:

plug means including a tapered member and an expandable sleeve member having a continuous wall disposed around the tapered member,

hydraulic actuator means having a piston member and a cylinder member, each of the members of the hydraulic actuator means coacting with one of the members ofthe plug means to force the sleeve member over the tapered member to expand the sleeve member into fluid sealing contact with the tube in which the plug means is disposed, and disconnectable coupling means for mechanically coupling one of said means to a source of hydraulic fluid under pressure whereby said one means may be disconnected from the source of hydraulic pressure after the plug means has been set. 2. The tool of claim 1 further characterized by: lance means for positioning the plug means at a remotely located position within the tube, and wherein said coupling means includes tensionable coupling means connecting the lance to one of the plug members, said tensionable coupling means being remotely disconnectable after the plug has been set in a remotely located position within the tube.

3. The tool of claim 2 wherein the lance means is connected to the tapered member by said coupling means, and the piston member and cylinder member are formed around the lance means.

4. The tool of claim 3 wherein Y the piston member and cylinder member are disposed around a portion of the lance means that is inserted in the tube, and

the lance means is arranged to conduct hydraulic fluid to the interior of the cylinder member.

5. The tool of claim 3 wherein the cylinder member is disposed around a portion of the lance means that is not inserted in the tube and the piston member is disposed around the lance means.

6. The tool of claim 5 wherein the lance means is comprised of a plurality of rod sections interconnected by tensionable couplings and the piston is comprised of tubular sections disposed around the interconnected rod sections.

7. The tool of claim 1 wherein the piston member is coupled to the tapered member by a remotely disconnectable coupling means.

8. The tool of claim 2 wherein the lance means is comprised of a plurality of tubular members interconnected by couplings adapted to transmit torque in at least one direction, and

the tensionable coupling means is a threaded coupling which is disconnected by rotation of the lance means in said one direction.

9. A tool for plugging a heat exchanger tube which comprises:

plug means comprising first and second interfitting members at least one of which expands into a fluid sealing engagement with the tube in which the plug means is located when the members are forced together,

lance means comprised of a plurality of sections interconnected by couplings adapted to transmit torque in at least one direction, coupling means connecting the lance to one of the members of the plug means that is disconnectable by torque applied to the lance in said at least one direction after the plug means has been set, and

means for forcing the other of the members of the plug means against said one member of the plug means to set the plug means in the tube.

10. The tool of claim 9 wherein said last mentioned means includes a tubular means disposed around the lance means for engaging said other of the members.

11. The tool of claim 10 wherein the tubular means is comprised of a plurality of sections and is generally coextensive with the lance means.

12. The tool of claim 10 wherein the tubular means is a piston disposed in an annular hydraulic cylinder, and

said annular hydraulic cylinder is adapted to be inserted in the tube being plugged.

13. A tool for plugging a heat exchanger tube which comprises:

plug means including a tapered member and an expandable sleeve member having a continuous wall disposed around the tapered member,

hydraulic actuator means having a piston member and a cylinder member, each of the members of the hydraulic actuator coacting with one of the members of the plug means to force the sleeve member over the tapered member to expand the sleeve member into fluid sealing contact with the tube in which the plug means is disposed, and

means associated with one of said members of said plug means for disconnecting the plug means from the hydraulic actuator means after the plug means has been set in the tube.

14. A tool for plugging a heat exchanger tube which comprises:

plug means including a tapered member and an expandable sleeve member having a continuous wall disposed around the tapered member, and

a hydraulic actuator means having a piston member and a cylinder member adapted to be inserted in the tube with the plug means, each of the members of the hydraulic actuator coacting with one of the members of the plug means to force the sleeve member over the tapered member to expand the sleeve member into fluid sealing contact with the tube in which the plug means is disposed. 

1. A tool for plugging a heat exchanger tube which comprises: plug means including a tapered member and an expandable sleeve member having a continuous wall disposed around the tapered member, hydraulic actuator means having a piston member and a cylinder member, each of the members of the hydraulic actuator means coacting with one of the members of the plug means to force the sleeve member over the tapered member to expand the sleeve member into fluid sealing contact with the tube in which the plug means is disposed, and disconnectable coupling means for mechanically coupling one of said means to a source of hydraulic fluid under pressure whereby said one means may be disconnected from the source of hydraulic pressure after the plug means has been set.
 2. The tool of claim 1 further characterized by: lance means for positioning the plug means at a remotely located position within the tube, and wherein said coupling means includes tensionable coupling means connecting the lance to one of the plug members, said tensionable coupling means being remotely disconnectable after the plug has been set in a remotely located position within the tube.
 3. The tool of claim 2 wherein the lance means is connected to the tapered member by said coupling means, and the piston member and cylinder member are formed around the lance means.
 4. The tool of claim 3 wherein the piston member and cylinder member are disposed around a portion of the lance means that is inserted in the tube, and the lance means is arranged to conduct hYdraulic fluid to the interior of the cylinder member.
 5. The tool of claim 3 wherein the cylinder member is disposed around a portion of the lance means that is not inserted in the tube and the piston member is disposed around the lance means.
 6. The tool of claim 5 wherein the lance means is comprised of a plurality of rod sections interconnected by tensionable couplings and the piston is comprised of tubular sections disposed around the interconnected rod sections.
 7. The tool of claim 1 wherein the piston member is coupled to the tapered member by a remotely disconnectable coupling means.
 8. The tool of claim 2 wherein the lance means is comprised of a plurality of tubular members interconnected by couplings adapted to transmit torque in at least one direction, and the tensionable coupling means is a threaded coupling which is disconnected by rotation of the lance means in said one direction.
 9. A tool for plugging a heat exchanger tube which comprises: plug means comprising first and second interfitting members at least one of which expands into a fluid sealing engagement with the tube in which the plug means is located when the members are forced together, lance means comprised of a plurality of sections interconnected by couplings adapted to transmit torque in at least one direction, coupling means connecting the lance to one of the members of the plug means that is disconnectable by torque applied to the lance in said at least one direction after the plug means has been set, and means for forcing the other of the members of the plug means against said one member of the plug means to set the plug means in the tube.
 10. The tool of claim 9 wherein said last mentioned means includes a tubular means disposed around the lance means for engaging said other of the members.
 11. The tool of claim 10 wherein the tubular means is comprised of a plurality of sections and is generally coextensive with the lance means.
 12. The tool of claim 10 wherein the tubular means is a piston disposed in an annular hydraulic cylinder, and said annular hydraulic cylinder is adapted to be inserted in the tube being plugged.
 13. A tool for plugging a heat exchanger tube which comprises: plug means including a tapered member and an expandable sleeve member having a continuous wall disposed around the tapered member, hydraulic actuator means having a piston member and a cylinder member, each of the members of the hydraulic actuator coacting with one of the members of the plug means to force the sleeve member over the tapered member to expand the sleeve member into fluid sealing contact with the tube in which the plug means is disposed, and means associated with one of said members of said plug means for disconnecting the plug means from the hydraulic actuator means after the plug means has been set in the tube.
 14. A tool for plugging a heat exchanger tube which comprises: plug means including a tapered member and an expandable sleeve member having a continuous wall disposed around the tapered member, and a hydraulic actuator means having a piston member and a cylinder member adapted to be inserted in the tube with the plug means, each of the members of the hydraulic actuator coacting with one of the members of the plug means to force the sleeve member over the tapered member to expand the sleeve member into fluid sealing contact with the tube in which the plug means is disposed. 